Describe how the graph of y=-1/4arccos(x-3)+1 is a transformation of y=arccos(x)

Noor brought 21 sheets of stickers. she gave 1/3 of a sheet to each of the 45 students at recess. she wants to give teachers 1 1/2 sheets each.

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

Indicate the formula for the following conditions: p^c(n,r)=